Update Next.js to 12 and switch to npm (#562)

* Update Commerce to Next.js 12

* Switch to npm

* Removed yarn

* Updated fetch type

* Fixed issue with BC deployment

package.json

@@ -5,7 +5,7 @@
     "dev": "NODE_OPTIONS='--inspect' next dev",
     "build": "next build",
     "start": "next start",
-    "analyze": "BUNDLE_ANALYZE=both yarn build",
+    "analyze": "BUNDLE_ANALYZE=both next build",
     "lint": "next lint",
     "prettier-fix": "prettier --write .",
     "find:unused": "npx next-unused",
@@ -21,7 +21,7 @@
   },
   "dependencies": {
     "@react-spring/web": "^9.2.1",
-    "@vercel/fetch": "^6.1.0",
+    "@vercel/fetch": "^6.1.1",
     "autoprefixer": "^10.2.6",
     "body-scroll-lock": "^3.1.5",
     "classnames": "^2.3.1",
@@ -33,7 +33,7 @@
     "lodash.debounce": "^4.0.8",
     "lodash.random": "^3.2.0",
     "lodash.throttle": "^4.1.1",
-    "next": "^11.0.0",
+    "next": "^12.0.3",
     "next-seo": "^4.26.0",
     "next-themes": "^0.0.14",
     "postcss": "^8.3.5",